Species profile
Least Killifish
Heterandria formosaLeast Killifish (Heterandria formosa) is a schooling community species for a cycled 10+ gallon freshwater aquarium. Plan for about 1.2 inches as an adult, 72-80°F water, pH 7-8.2, and beginner-friendly care. Keep a group of at least 6; larger groups often behave more naturally when the tank has room.
Community leaningBeginner-friendly care
10 galMinimum tank
1.2 inAdult size
6Schooling minimum
72-80°FTemperature
Water Range
- pH
- 7-8.2
- GH
- 8-25 dGH
- KH
- 5-18 dKH
Behavior
- Temperament
- Peaceful
- Fin nipping
- 0/5
- Territory
- 0/5
Diet and Care
- Diet
- omnivore
- Diet difficulty
- 1/5
- Care difficulty
- 1/5
Planning Notes
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These matches are starting points with overlapping water ranges and lower behavior risk. Always check the full stocking plan, tank size, and group counts before buying.
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